I really do think pinching back regularly, doing the Chelsea chop, choosing varieties that are slightly shorter(.e.g. Heleniums) removing long stems on dahlia and choosing plants that stand up to the wind (e.g. Acteas) is the way to go.

I have lots,of tall and very tall perennials in the garden amd all are still in fine fettle. Cannas, bonariensis, veronicastrums , agastaches all do well against wind as do many tall grassss that aren't a bit miffed about wind or rain.

Get rid of that hedge Ian and plant something else. those conifers will not regrow and anything planted with it will look odd and fiddly and sick

I would use euonymous aureus, Taxus ( the dark green,,almost funereal one), escallonia, golden king holly, or Lonicera nitida battlesons gold. However, check out golden privet. This is a surprisingly attractive shrub.....during spring and summer it looks delightful and is easy to maintain.